Disclosed is a heat sink for a lighting device, which radiates the heat generated from the lighting device, comprising: an outer case coupled to the lighting device; an inner case accommodated into the outer case in such a manner as to be spaced apart therefrom to form a filling space between the inner case and the outer case; and a cooling medium vaporized on a portion of the outer case coupled to the lighting device by means of the heat generated from the lighting device to cool the lighting device.